One thing that I learned at the Shepherd's Path seminar I went to a few months back was that Muhammad (saws) used to treat each of his Companions like they were his favorite. For instance, Abdullah bin 'Amr bin al-'As said that whenever the Prophet (saws) would look at him, he would smile, which made him think that he was the favorite of the Prophet (saws).
To test his theory, one day he asked the Prophet (saws) if he was better than Abu Bakr, but the Prophet (saws) responded that Abu Bakr was better. And then he asked if he was better than 'Umar, but the Prophet (saws) told him that 'Umar was better.
Then he realized that this was the way that the Prophet (saws) was towards everyone.
The lesson was that we should treat all our brothers and sisters in Islam this way--like they are our favorite person to be around. And honestly, it's a real treat to be around someone who treats you that way.
Image a person who smiles whenever he sees you. Or whenever she sees you, if you're a sister. A person who rushes to hug you, and greets you like you were the person they'd been looking for. Every single time they see you. It's a different kind of favoritism--not favoring one person over everyone else, but making everyone to feel as if they are your favorites.
People love that kind of attention--it's true. Hearing that story about 'Abdullah bin 'Amr bin al-'As puts it into a new perspective, thinking about how the Prophet (saws) acted around his Companions, and why they loved him so much.